.TH std::experimental::filesystem::is_symlink 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::experimental::filesystem::is_symlink \- std::experimental::filesystem::is_symlink

.SH Synopsis
   Defined in header <experimental/filesystem>
   bool is_symlink( file_status s );                 \fB(1)\fP (filesystem TS)
   bool is_symlink( const path& p );                 \fB(2)\fP (filesystem TS)
   bool is_symlink( const path& p, error_code& ec );

   Checks if the given file status or path corresponds to a symbolic link, as if
   determined by the POSIX S_IFLNK.

   1) Equivalent to s.type() == file_type::symlink.
   2) Equivalent to is_symlink(status(p)) or is_symlink(status(p, ec)).

.SH Parameters

   s  - file status to check
   p  - path to examine
   ec - out-parameter for error reporting in the non-throwing overload

.SH Return value

   true if the file indicated by p or if the type indicated s refers to a symbolic
   link. The non-throwing overload returns false if an error occurs.

.SH Exceptions

   1)
   noexcept specification:
   noexcept

   2) The overload that does not take an error_code& parameter throws filesystem_error
   on underlying OS API errors, constructed with p as the first argument and the OS
   error code as the error code argument. std::bad_alloc may be thrown if memory
   allocation fails. The overload taking an error_code& parameter sets it to the OS API
   error code if an OS API call fails, and executes ec.clear() if no errors occur. This
   overload has
   noexcept specification:
   noexcept


.SH Notes

   The information provided by this function is usually also provided as a byproduct of
   directory iteration. During directory iteration, calling is_symlink(*iterator) is
   less efficient than is_symlink(iterator->status()).

.SH Example


// Run this code

 #include <cstdio>
 #include <cstring>
 #include <experimental/filesystem>
 #include <fstream>
 #include <iostream>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
 #include <unistd.h>

 namespace fs = std::experimental::filesystem;

 void demo_status(const fs::path& p, fs::file_status s)
 {
     std::cout << p;
     // alternative: switch(s.type()) { case fs::file_type::regular: ... }
     if (fs::is_regular_file(s))
         std::cout << " is a regular file\\n";
     if (fs::is_directory(s))
         std::cout << " is a directory\\n";
     if (fs::is_block_file(s))
         std::cout << " is a block device\\n";
     if (fs::is_character_file(s))
         std::cout << " is a character device\\n";
     if (fs::is_fifo(s))
         std::cout << " is a named IPC pipe\\n";
     if (fs::is_socket(s))
         std::cout << " is a named IPC socket\\n";
     if (fs::is_symlink(s))
         std::cout << " is a symlink\\n";
     if (!fs::exists(s))
         std::cout << " does not exist\\n";
 }

 int main()
 {
     // create files of different kinds
     fs::create_directory("sandbox");
     std::ofstream("sandbox/file"); // create regular file
     fs::create_directory("sandbox/dir");
     mkfifo("sandbox/pipe", 0644);
     struct sockaddr_un addr;
     addr.sun_family = AF_UNIX;
     std::strcpy(addr.sun_path, "sandbox/sock");
     int fd = socket(PF_UNIX, SOCK_STREAM, 0);
     bind(fd, (struct sockaddr*)&addr, sizeof addr);
     fs::create_symlink("file", "sandbox/symlink");

     // demo different status accessors
     for (auto it = fs::directory_iterator("sandbox"); it != fs::directory_iterator(); ++it)
         demo_status(*it, it->symlink_status()); // use cached status from directory entry
     demo_status("dev/null", fs::status("/dev/null")); // direct calls to status
     demo_status("dev/sda", fs::status("/dev/sda"));
     demo_status("sandbox/no", fs::status("/sandbox/no"));

     // cleanup
     close(fd);
     fs::remove_all("sandbox");
 }

.SH Possible output:

 "sandbox/file" is a regular file
 "sandbox/dir" is a directory
 "sandbox/pipe" is a named IPC pipe
 "sandbox/sock" is a named IPC socket
 "sandbox/symlink" is a symlink
 "dev/null" is a character device
 "dev/sda" is a block device
 "sandbox/no" does not exist

.SH See also

   status            determines file attributes
   symlink_status    determines file attributes, checking the symlink target
                     \fI(function)\fP
   file_status       represents file type and permissions
                     \fI(class)\fP
   status_known      checks whether file status is known
                     \fI(function)\fP
   is_block_file     checks whether the given path refers to block device
                     \fI(function)\fP
   is_character_file checks whether the given path refers to a character device
                     \fI(function)\fP
   is_directory      checks whether the given path refers to a directory
                     \fI(function)\fP
   is_fifo           checks whether the given path refers to a named pipe
                     \fI(function)\fP
   is_other          checks whether the argument refers to an other file
                     \fI(function)\fP
   is_regular_file   checks whether the argument refers to a regular file
                     \fI(function)\fP
   is_socket         checks whether the argument refers to a named IPC socket
                     \fI(function)\fP
   exists            checks whether path refers to existing file system object
                     \fI(function)\fP
                     cached status of the file designated by this directory entry
   status            cached symlink_status of the file designated by this directory
   symlink_status    entry
                     \fI\fI(public member\fP function of\fP
                     std::experimental::filesystem::directory_entry)

.SH Categories:
     * Noindexed pages
     * unconditionally noexcept
.SH Hidden categories:
     * Pages with unreviewed unconditional noexcept template
     * Pages with unreviewed noexcept template
